Fire Hydrant Flow Calculator
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psi before flowing
Residual: psi while flowing
Pitot: pitot gage reading
Diameter: size of opening tested
This hydrant is flowing: GPM from the test outlet
Projected available hydrant flow: GPM Note 1
2nd Static: secondary psi before flowing
2nd Residual: secondary psi while flowing
The main can be expected to flow about: GPM

  1. Projected available flows calculated at 20 psi residual, or the static pressure for low pressure hydrants having static pressures of less than 40 psi.